From German Pat. 692 121 an internal combustion engine is known that has a supercharger consisting of a centrifugal blower in which an injection nozzle is arranged on the pressure side in the line leading from the supercharger to the engine, namely inside the blower directly after the rotor, at the beginning of a spiral that opens into a mixture line leading into one or more cylinders of the internal combustion engine. In this spiral, which serves to collect the output from the supercharger rotor and to convert its kinetic energy into energy of compression, the air has already been warmed enough to avoid ice formation, which could harm the supercharger and is often unavoidable when the mixture is injected into the suction line before the supercharger owing to the strong cooling of the air by the volatilisation of the fuel. This ice formation is particularly troublesome in the case of turbochargers running at high speed. The velocity of the air, which is important for producing turbulence and/or intimate mixing with the fuel, is of course lower on the pressure side of the supercharger than, for example, in the suction channel before the supercharger, and this is disadvantageous, particularly during idling when the velocity is low anyway. Nevertheless the air velocity is higher compared with an injection nozzle arranged still further from the supercharger on the pressure side, namely in the mixture line.